Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Studies of ancient DNA and endogenous viral elements have revealed extraordinary conservation of virus genome sequences over thousands or millions of years. In this Opinion article, Simmonds, Aiewsakun and Katzourakis describe a niche-filling model that describes how viruses can rapidly evolve to adapt to new host environments while their longer-term evolution is increasingly driven by their hosts.
In this Opinion article, Banerjee et al. explore the importance of microbial keystone taxa and keystone guilds in microbiome structure and functioning, describe challenges in the characterization and manipulation of such taxa, and propose a definition of keystone taxa in microbial ecology.
The microbiota can influence host behaviour through the gut–brain axis. In this Opinion, Johnson and Foster explore the evolution of this relationship and propose that adaptations of competing gut microorganisms may affect behaviour as a by‑product, leading to host dependence.
Interactions among organisms are not limited to the exchange of electron donors. Most microorganisms are auxotrophs and thus rely on external nutrients for growth. In this Opinion article, Zengler and Zaramela postulate that auxotrophies and nutrient requirements among members of complex communities have profound implications for microbial interactions and thus the overall microbial network.
